Polyalkylated benzenes normally are prepared by Friedel-Crafts alkylation. Hexamethylbenzene has been prepared in good yield by the reaction of phenol and excess methanol over alumina at 320.degree. C..sup.(1) FNT .sup.(1) A. P. Krysin and V. A. Koptyug, Izvestiyr Akad. Nauk SSSR, Ser. Khim., No. 7, 1957 (1969); Chem. Abstr. 71, 112540 y (1969).
It is known that mesitylene (1,3,5-trimethylbenzene) can be prepared by reacting acetone in the vapor phase using a catalyst, such as alumina.
My invention is directed to a process for preparing penta- and hexaalkylbenzenes, and particularly penta- and hexamethylbenzenes.
Hexamethylbenzene is useful in that it can be converted to a useful polyimide. The hexamethylbenzene is oxidized to dimethylpyromellitic acid which in turn is converted to the polyimide.
The penta- and hexaalkylbenzenes are useful as lubricants and transformer oils.